1. Field of the Invention
The present invention relates to gas igniters and more particularly to a gas igniter which uses a glow plug for igniting combustible gases emitted by welding torches.
2. Description of the Related Art
Commonly, the lighting of conventional gas torches for welding, cutting, etc., is accomplished by flint lighters in which the operator must strike a spark with the flint while holding the torch close to the flint. These flint lighters have certain inherent disadvantages. For example, the operator is not always able to quickly strike a sufficient spark to enable him to quickly light his torch. In addition, the operator must handle both the torch and the flint lighter at the same time, which is awkward and inconvenient. Also, the flints wear out and must be replaced. Additionally, the use of flint lighters normally requires that both hands of the operator be occupied which is highly undesirable in certain operations. Furthermore, use of these flint lighters generally require the operator's hand to be positioned in close proximity to the torch which may result in painful burning of the hand of the operator.
In view of these safety problems several hand-held electric ignition devices have been developed which allow the operator to keep his hands well away from the torch. For example, U.S. Pat. No. 3,919,522 discloses a cordless electric ignition tool having a handle portion comprising a housing containing a battery, a pair of terminals and a normally open switch in circuit with the battery and the terminals.
U.S. Pat. No. 874,357, discloses another hand-held lighter. The '357 lighter includes a hollow body and means associated with the body for closing an electric circuit associated with the body with either a resistance in or out of the same. This introduction of resistance helps prevent injury to the hollow body.
Although helping to reduce the possibility of the operator burning his hand these hand-held designs still require the operator to use both his hands. U.S. Pat. No. 3,090,856, entitled "GAS TORCH LIGHTER", issued to H. Rorvig, discloses a torch lighter having a housing which is fastened to a workbench. The housing has a heating unit mounted on the top thereof. The heating or igniting unit includes a coil of high resistance wire such as Nichrome which is wound about a suitably insulated mounting block. The torch lighter includes electrical cables and a suitable plug for connecting it to a source of electric current.
The igniting coil is enclosed by a hood for confining the gas from the torch in the area immediately surrounding the igniting coil to permit quick igniting or lighting thereof. A switch unit is also mounted atop the box in front of the heating unit and preferably in substantial alignment therewith. This switch unit comprises a pair of circuit breakers, each having opposed, disconnected convex ends defining therebetween a valley or seat for receiving the tip or nozzle of a gas torch.
To light the torch, the operator rests the tip of the gas torch in the valley provided by the convex ends to bridge the gap with the nozzle directed towards the heating unit. The engagement of the tip of the torch with the contact elements closes the circuit of the torch lighter and causes the heating coil to heat to a high temperature sufficient to ignite the gas from the torch.
Although the Rorvig device obviates many of the difficulties inherent with prior art torch igniters, there is substantial room for improvement. The Rorvig device is dependent upon an external electric source. Use of an electrical cord at a welding table can be very dangerous. Furthermore, it is secured to the workbench and cannot easily be moved from one location to another. Additionally, the hood for enclosing the igniting coil is relatively wide, shallow, and of a rectangular cross-section and consequently does little to control the direction of the flame.